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The query [[Category:ENS Notification]] [[Reactor type::GE-5]] [[Scram::+]] was answered by the SMWSQLStore3 in 0.0324 seconds.


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 Entered dateSiteScramRegionReactor typeEvent description
ENS 5341018 May 2018 13:27:00ColumbiaAutomatic ScramNRC Region 4GE-5At 0651 (PDT) on May 18th, 2018, Columbia Generating station experienced a Main Transformer trip, that caused a Reactor Scram. Reactor Power, Pressure and Level were maintained as expected for this condition. MS-RV-1A (Safety Relief Valve) and MS-RV-1B (Safety Relief Valve) opened on reactor high pressure during the initial transient. MS-RV-1B appeared to remain open after pressure lowered below the reset point. The operating crew removed power supply fuses for MS-RV-1B and it currently indicates intermediate position. SRV (Safety Relief Valve) tail pipe temperatures indicate all valves are closed. Suppression pool level and temperature have remained steady within normal operating levels. All control rods inserted and reactor power is being maintained subcritical. RPV (Reactor Pressure Vessel) water level is being maintained with condensate and feed system with startup flow control valves in automatic. Reactor Pressure is being maintained with the Turbine Bypass valves controlling in automatic. The main condenser is the heat sink. No ECCS (Emergency Core Cooling Systems) systems actuated or injected; the EOC-RPT (End of Cycle-Recirculation Pump Trip) and RPS (Reactor Protection System) systems actuated causing a trip of the RRC pumps and a reactor scram. Core recirculation is being maintained with RRC-P-1A (Reactor Recirculation Pump) running. No release has occurred. At this time there will be no notifications to state, local or other public agencies. The NRC Senior Resident has been notified. The cause of the event is currently under investigation. Plant conditions are stable. The plant is in its normal electrical alignment and offsite power is available to the site.
ENS 5291820 August 2017 22:46:00ColumbiaManual ScramNRC Region 4GE-5

On August 20, 2017 at 1605 PDT, Columbia Generating Station was manually scrammed from 100 percent power due to a rise of Main Condenser back pressure. Manual scram of the unit is procedurally required upon a loss of Main Condenser back pressure. Preliminary investigations indicate that the Main Condenser air removal suction valve (AR-V-1) closed, resulting in the Condenser back pressure rising to within 1.0 inch Hg of the setpoint with reactor power greater than 25 percent. Further investigations continue. All control rods fully inserted. In addition to the closure of the air removal suction valve, one of two Reactor Feedwater startup flow control valves did not adequately operate to control Reactor vessel level and resulted in a high-level (Level-8) actuation tripping the Reactor Feedwater System. All other systems operated as expected. Reactor water level is currently being controlled manually with the start-up level control isolation valve. AR-V-1 has been manually opened with a jumper and temporary air supply. Reactor decay heat is being removed via bypass valves to the Main Condenser. This event is being reported under the following: 10 CFR 50.72(b)(2)(iv)(B), which requires a four-hour notification for any event or condition that results in actuation of the Reactor Protection System when the reactor is critical. The licensee notified the NRC Resident Inspector. The licensee plans to issue a press release.

  • * * UPDATE ON 8/24/17 AT 1937 EDT FROM MATT HUMMER TO DONG PARK * * *

The licensee is updating the notification to include an 8 hour notification under 10 CFR 50.72(b)(3)(iv)(A) for a specified system actuation due to a Level 3 isolation signal which occurred approximately 20 minutes after the scram. The licensee is currently in cold shutdown to repair the Reactor Feedwater startup flow control valve. The licensee has notified the NRC Resident Inspector. Notified R4DO (Farnholtz).

ENS 528896 August 2017 00:26:00Nine Mile PointAutomatic ScramNRC Region 1GE-5At 2235 (EDT) Nine Mile Point Unit 2 experienced an automatic scram on high reactor pressure. Turbine stop valve testing was in progress at the time of the scram. All control rods inserted. Pressure control is via the turbine bypass valves. The cause of the scram is being investigated. This is a 4-Hour report for 10CFR50.72(b)(2)(iv)(B) RPS (Reactor Protection System) Actuation. The NRC Resident Inspector has been notified. Reactor water level is being maintained with normal feedwater flow. No safety or relief valves lifted. The plant is in its normal shutdown electrical lineup.
ENS 5256418 February 2017 02:58:00LaSalleManual Scram
Automatic Scram
NRC Region 3GE-5

This notification is being provided in accordance with 10CFR 50.72(b)(2)(iv)(B). On February 17, 2017 at 2353 CST, Unit 1 Reactor Automatic Scram signal was received due to Turbine Control Valves Fast Closure. The turbine trip was due to receipt of Level 8 Trip due to a failure of the Feedwater Regulating Valve to Full open. Plant is in a stable condition with reactor pressure being maintained by the Turbine Bypass valves. Reactor water level is being controlled with Feedwater thru the Low Flow Feedwater Regulating Valve. Further investigation into the cause of the event is in progress. All control rods fully inserted, and decay heat is being removed via steam to the main condenser using bypass valves. The licensee has notified the NRC Resident Inspector.

  • * * UPDATE FROM BROCK POLLMANN TO HOWIE CROUCH AT 1721 EDT ON 4/14/17 * * *

Upon further review of the event data, it was determined that the Nuclear Station Operator (NSO) had initiated a manual scram, which was followed by a Turbine Control Valve (TCV) fast closure automatic scram when the turbine tripped. The licensee has notified the NRC Resident Inspector. Notified R3DO (Jeffers).

ENS 5254714 February 2017 02:40:00LaSalleAutomatic ScramNRC Region 3GE-5This notification is being provided in accordance with 10 CFR 50.72(b)(2)(iv)(B). On February 13, 2017 at 2309 CST, a Unit 1 Reactor Automatic Scram signal was received due to Turbine Control Valve Fast Closure. The turbine trip was due to the main generator trip on Differential Current. The 'U' safety relief valve actuated in the relief mode on the turbine trip, and has subsequently reset with tailpipe temperature returning to normal. The plant is in a stable condition with reactor pressure being maintained by the Turbine Bypass valves. Reactor water level is being controlled with feedwater. Investigation into the cause of the event is in progress. All control rods fully inserted on the scram. Unit 1 is in a normal shutdown electric plant alignment. Unit 2 was not affected. The licensee notified the NRC Resident Inspector.
ENS 5250523 January 2017 10:34:00LaSalleManual ScramNRC Region 3GE-5This notification is being provided pursuant with 10 CFR 50.72 (b)(2)(iv)(B). (On January 23, 2017) at 0806 (CST), Unit 2 Manual Scram was inserted due to a Stator Water Cooling runback signal and a Turbine Bypass Valve opening. The Plant is stable, reactor pressure is being maintained with Bypass valves. Reactor water level is being controlled with feedwater. Investigation into the cause of the event is in progress. All control rods fully inserted. The licensee has notified the NRC Resident Inspector.
ENS 5244218 December 2016 18:13:00ColumbiaAutomatic ScramNRC Region 4GE-5On December 18, 2016 at time 1124 PST the plant experienced a full reactor scram. Preliminary investigations indicate that the scram was caused by a load reject from the Bonneville Power Administration (BPA) Ashe substation. Further investigations continue. The following conditions have occurred: Turbine Governor valve closure Reactor high pressure trip +13 inches reactor water level activations E-TR-B (backup transformer) supplying E-SM-7/SM-8 (vital power electrical busses) Complete loss of Reactor Closed Cooling (RCC) E-TR-S (Startup transformer) supplying SM-1/2/3 (non-vital power electrical busses) E-DG-1/2/3 (emergency diesel generators) auto start Low Pressure Core Spray (LPCS) and Residual Heat Removal (RHR) A/B/C initiation signals Main Steam Isolation Valves (MSIV) are closed Reactor Core Isolation Cooling (RCIC) RCIC and High Pressure Core Spray (HPCS) were manually activated and utilized to inject and maintain reactor water level. Pressure control is with Safety Relief Valves (SRV) in, manual. Level control is with RCIC and Control Rod Drive (CRD). RCIC has experienced an over speed trip that was reset so that level control could be maintained by RCIC. This event is being reported under the following: 10 CFR 50.72(b)(2)(iv)(A) which requires a 4 hour notification for Emergency Core Cooling System (ECCS) discharge into the reactor coolant system. 10 CFR 50.72(b)(2)(iv)(B) which requires a 4 hour notification for any event or condition that results in actuation of the Reactor Protection System (RPS) when the reactor is critical. 10 CFR 50.72(b)(3)(iv)(A) which requires an 8 hours notification for actuation of ECCS systems. All control rods fully inserted. The NRC Resident Inspector has been informed. The licensee indicated that no increase in radiation levels were detected.
ENS 5182628 March 2016 19:44:00ColumbiaManual ScramNRC Region 4GE-5At 1322 PDT on Monday, March 28, 2016, Columbia Generating Station was manually scrammed from 100% thermal power due to the loss of Reactor Closed Cooling (RCC). Manual scram of the unit is procedurally required upon loss of RCC. The cause of the loss of RCC is being investigated. Regulation 10 CFR 50.72(b)(2)(iv)(B) requires reporting within 4 hours of any event or condition that results in actuation of the Reactor Protection System (RPS) when the reactor is critical. All control rods were fully inserted. Valve RWCU-V-4 automatically closed upon high water temperature due to loss of RCC flow. No other safety system actuations were reported. All systems operated as expected. Reactor decay heat is being removed via bypass valves to the Main Condenser. The station is in normal shutdown electrical lineup. The NRC Resident Inspector has been informed. No safety/relief valves lifted and no emergency core cooling systems injected following the reactor scram.
ENS 5083018 February 2015 16:01:00Nine Mile PointManual ScramNRC Region 1GE-5At 1406 (EST) Nine Mile Point Unit 2 inserted a manual scram due to rapidly rising reactor water level. The cause of the rapidly rising water prior to the manual scram is unknown and under investigation. Reactor water level is currently being maintained in normal control band post scram. The reactor scram is reportable in accordance with 10 CFR 50.72(b)(2)(iv)(B) as, 'Any event or condition that results in actuation of the reactor protection system (RPS) when the reactor is critical.' The NRC Resident has been notified. All rods fully inserted. Nine Mile Point Unit 2 is in a normal electrical shutdown configuration. The licensee reported no impact on Unit 1. The New York State Public Service Commission was also notified.
ENS 498684 March 2014 05:05:00Nine Mile PointManual ScramNRC Region 1GE-5At 0137 EST Nine Mile Point Unit 2 experienced a loss of an uninterruptible power supply 2VBB-UPS3B which resulted in a half scram and half isolations. This caused a loss of cooling water to the Reactor Recirculation Pumps and other indications for the loss of power. At 0143 EST a Manual Reactor Scram was inserted due to the rise of temperatures on the Reactor Recirculation Pump seal cavity temperature and motor winding temperature. The reactor building ventilation radiation monitor went non-functional when the reactor building isolated on the loss of UPS power. The standby gas treatment system was started as required and restored the reactor building differential pressure. This is a 4-Hour report for 10CFR50.72(b)(2)(iv)(B) RPS Actuation and 8-Hour report for 10CFR50.72(b)(3)(xiii) Loss of Emergency Assessment Capability. The NRC Resident inspector has been notified. All systems functioned as required following the manual scram. All control rods fully inserted. The cause of the loss of the UPS is under investigation.
ENS 495932 December 2013 11:03:00Nine Mile PointManual ScramNRC Region 1GE-5At 0904 (EST) on Monday, December 2, 2013, Nine Mile Point Unit 2 was manually scrammed from approximately 40% thermal power due to the loss of both reactor recirculation pumps during a planned downpower evolution. Manual scram of the unit is procedurally required upon loss of both recirculation pumps to avoid potential power/flow oscillations. The reactor recirculation pumps failed to transfer to the low frequency motor generators when downshifted from fast speed. The cause of the loss of both reactor recirculation pumps is not known at this time. (Nine Mile Point Unit 2) NMP2 has commenced cooldown in preparation for the forced outage to investigate and commence repairs. 10 CFR 50.72(b)(2)(iv)(B) requires reporting within 4 hours of any event or condition that results in actuation of the reactor protection system (RPS) when the reactor is critical. All control rods fully inserted. No safety systems actuated. Decay heat is being removed via the main condenser. The "A" recirculation pump was restarted in low speed at 1045 EST. Unit 2 is in a normal shutdown electrical lineup. The licensee informed the NRC Resident Inspector and will inform the New York State Public Services Commission.
ENS 4896925 April 2013 22:23:00LaSalleManual ScramNRC Region 3GE-5This report is being made pursuant to 10CFR50.72(b)(2)(iv)(B), RPS Actuation (scram). At 2019 CDT on April 25, 2013, LaSalle Unit 2 was manually scrammed due to a loss of Condenser Circulating Water. The Unit was manually scrammed after the condenser circulating water pumps tripped due to high level in the turbine building condenser pit. The high level in the condenser pit was caused by a leak on the upper manway of the condenser water box during a maintenance activity. MSIV's were isolated due to loss of heat sink. The safety relief valves were used in pressure control mode. Current plant status: reactor level is stable and reactor pressure is stable. The condenser water box manway leak has been isolated. The plant will remain in hot shutdown pending investigation and repairs. Reactor Core Isolation Cooling (RCIC) is being used in the pressure control mode. The licensee has notified the NRC Resident Inspector.
ENS 4893917 April 2013 16:59:00LaSalleAutomatic ScramNRC Region 3GE-5

LaSalle Unit 1 and LaSalle Unit 2 have both experienced an automatic reactor scram, in conjunction with a loss of offsite power. This was caused by an apparent lightning strike in the main 345kV/138kV switchyard during a thunderstorm. 138kV line 0112 has been inspected in the field, and heavy damage has been noted on the insulators on two of the three phases on a line lightning arrestor line side. The plant systems have all responded as expected. All five diesel generators started, and have loaded on to their respective buses as designed. All rods went full in on both units during the respective scrams. HPCS (High Pressure Core Spray) system was started on each unit and automatically aligned for injection for initial level control. The MSIVs (Main Steam Isolation Valves) are shut on both units with decay heat being removed via the safety relief valves. Suppression pool cooling is in progress. The licensee will notify the NRC Resident Inspector and has notified the State. Notified DHS, FEMA, USDA, HHS, DOE, NICC, EPA, and Nuclear SSA via email.

  • * * UPDATE FROM DON PUCKETT TO VINCE KLCO AT 2113 EDT ON 4/17/2013 * * *

In addition to information (previously provided), LaSalle Unit 2 received a high drywell pressure signal (1.77 psig) due to loss of containment cooling from the loss of power. At the time of this high drywell pressure signal, high pressure core spray pump and 2B residual heat removal (RHR) pump was already in operation, the low pressure core spray system and 2A residual heat removal system was secured and (placed) in pull to lock. When the signal was satisfied the ECCS (Emergency Core Cooling Systems) signal was processed but only the 2C RHR pump would have started. In this case, the 2C RHR pump tripped when the signal was received. There is no evidence of reactor coolant leakage. There was no additional ECCS systems discharging into the RCS (Reactor Coolant System). As (initially stated), level was controlled using High Pressure Core Spray and level control is now being maintained using the Reactor Core Isolation Cooling (RCIC) systems. The 2C RHR pump trip is under investigation. Due to the initial loss of offsite power for both Unit 1 and Unit 2 reported at 1511 (CDT), multiple containment isolation valves isolated and closed as expected. Once initial containment isolations were verified, two Unit 2 primary containment vent and purge valves were opened to vent the Unit 2 containment. Once Unit Two containment pressure reached 1.77 (psig), these two vent valves isolated as expected. Due to the loss of offsite power, the Station Vent Stack Wide Range Gas Monitor (WRGM) and the Standby Gas Treatment Wide Range Gas Monitor (VGWRGM) also lost power. Manual sampling has been implemented and power is restored to the VGWRGM, however the VGWRGM has not been declared operable yet. Normal radiation levels have been reported from the manual sampling. (This is being reported in accordance with 10CFR50.72(b)(3)(xiii).) The licensee notified the NRC Resident Inspector and the State of Illinois. Notified the R3 IRC, NRR EO(Skeen), IRD MOC (Grant).

  • * * UPDATE AT 0057 EDT ON 04/18/13 FROM MIKE LAWRENCE TO S. SANDIN * * *

After the Unit 2 primary containment vent and purge system isolated on the Unit 2 containment High Pressure signal, Venting of the Unit 1 primary containment was commenced. At 2005 CDT, Unit 1 primary containment pressure reached the Group 2 primary containment isolation system setpoint (1.77 PSIG) causing the primary containment vent and purge valves being used to vent the Unit 1 containment to isolate. Unit 1 primary containment venting was being performed through the Standby Gas Treatment system which is a filtered system. In addition to the primary containment isolation signal on high drywell pressure, an ECCS initiation on high drywell pressure also occurred. The ECCS signal resulted in an auto start of the 1C RHR system. The 1B RHR system was already running in suppression pool cooling mode. 1A RHR and LPCS had been secured to prevent overloading the common diesel generator for division 1. The common diesel generator supplies both Unit 1 and Unit 2 division 1 ESF busses. The licensee informed the NRC Resident Inspector. Notified NRR EO (Skeen), IRD MOC (Grant) and R3IRC (Louden).

  • * * UPDATE AT 0947 EDT ON 04/18/13 FROM JUSTIN FREEMAN TO PETE SNYDER * * *

LaSalle has terminated the unusual event which was initiated at 1511 on 4/17/13 and reported under EN 48939. This unusual event has been terminated based on meeting the following established criteria. This report is being made in accordance with 10CFR50.72.(c)(1)(iii). 1) Off-site power has been restored to all ESF busses 2) Fuel Pool Cooling has been restored on both units 3) Primary Containment Chillers have been restored on both units 4) Drywell pressure is less than ECCS initiation setpoint 5) ECCS signals cleared to allow diesels to be placed in stand by Recovery of remaining plant systems will be managed through the Outage Control Center (OCC)." The licensee informed the NRC Resident Inspector. Notified R3DO (Orth), NRR EO (Chernoff), IRD (Grant), DHS, FEMA, USDA, HHS, DOE, NICC, EPA, and Nuclear SSA via email.

  • * * UPDATE AT 1711 EDT ON 4/21/2013 FROM GREG LECHTENBERG TO MARK ABRAMOVITZ * * *

In addition to the 10 CFR 50.72 Sections initially identified, the Loss of Offsite Power was also reportable under 10 CFR 50.72(b)(3)(v)(D) as an event or condition that could have prevented the fulfillment of the safety function of systems needed mitigate the consequences of an accident. This event is considered a safety system functional failure for both Units 1 and 2. The licensee will notify the NRC Resident Inspector. Notified the R3DO (Orth).

ENS 4809712 July 2012 04:49:00Nine Mile PointManual ScramNRC Region 1GE-5On July 12, 2012, at 0200 EDT, clean steam reboiler 'B' failed, causing a loss of sealing steam. This resulted in degrading condenser vacuum and rising off gas system pressure. The main steam backup supply for sealing steam also failed, and condenser vacuum and off gas system pressure continued to degrade. In response to rising off gas system pressure and lowering condenser vacuum, reactor power was lowered to 85% in accordance with Special Operating Procedures. With off gas system pressure approaching the procedural limit and condenser vacuum degrading rapidly, a manual reactor scram was inserted at 0220 EDT. All control rods fully inserted and all systems functioned as expected on the scram. Plant is currently shutdown and parameters are stable. The unit is currently implementing post scram recovery procedures and plant cooldown is in progress. The cause of the loss of both the primary and backup sources of sealing steam is under investigation. The shutdown electrical lineup is normal and decay heat is being removed via steam bypass valves to the main condenser. The licensee has notified the NRC Resident Inspector and the Public Service Commission.
ENS 4714111 August 2011 01:05:00Nine Mile PointManual ScramNRC Region 1GE-5

NMP2 inserted a manual reactor scram due to a through wall leak on feedwater pump 2FWS-P1A minimum flow line. 2FWS-P1A has been removed from service to minimize the leak. All control rods inserted and all systems functioned as designed. The unit will remain in hot shutdown until plant startup. All systems functioned as required and the scram was uncomplicated. The licensee plans to issue a press release and has informed the NRC Resident Inspector and the New York State Public Service Commission.

  • * * UPDATE AT 1035 EDT ON 8/11/11 FROM MANLEY TO HUFFMAN * * *

The licensee will not be issuing a press release regarding this manual scram. R1DO (Powell) notified.

ENS 456127 January 2010 04:38:00Nine Mile PointScramNRC Region 1GE-5At 0100, Nine Mile Point Unit 2 reactor scrammed (on low reactor water level). The cause is currently under investigation. Maintenance activities were in progress on Residual Heat Removal (RHR) B & C systems. It is suspected that transmitter venting is the most probable cause of the trip. Reactor core isolation system (RCIC) injected on invalid level 2 signal. No safety relief valves (SRV's) actuated. B and C Residual Heat Removal systems (RHR) remain inoperable. All other ECCS systems and Emergency Diesel Generator are currently operable. Reactor water level is normal. No emergency core cooling system injection was required. The plant is currently in the hot shutdown condition. No emergency plan activation is required. Activation of forced outage plan is in progress. Lowest reactor water level reached during the transient was 140 inches. This is less than the reactor water level scram set point of 159.3 inches. Reactor pressure before scram was 1020 psig, current reactor pressure is 530 psig and reactor coolant temperature is 470 degrees F. Plant stack monitor is not available. Last grab sample reading at time 0257 is 857 micro-curies/sec. All systems functioned as required. All rods fully inserted on trip. Decay heat is being removed by steaming to the main condenser. The plant is in its normal shutdown electrical lineup. The licensee notified the NRC Resident Inspector.
ENS 454847 November 2009 12:57:00ColumbiaManual ScramNRC Region 4GE-5At 0725 hours, a manual scram was inserted due to a Main Turbine Digital Electro-Hydraulic (DEH) control system leak and anticipated turbine trip on loss of DEH tank level. Initial investigation identified a DEH leak at the area of the Quad-Voter hydraulic trip subsystem on the high pressure turbine. All rods fully inserted, main steam isolation valves (MSIVs) remained open, no safety/relief valves (SRVs) opened, and all other safety systems operated as designed. Reactor water level was restored and maintained with the Reactor Feedwater and Condensate systems during the post-scram transient within normal operating bands. Reactor pressure was controlled using main steam drain lines. A normal cooldown to the condenser is in progress. Offsite power is available. All three emergency diesel generators are operable and available. The plant was operating at 52% for planned maintenance. All safety systems remain available. The licensee has notified the NRC Resident Inspector.
ENS 4526515 August 2009 20:06:00LaSalleAutomatic ScramNRC Region 3GE-5At 1606 CDT on August 15, 2009, LaSalle Unit 2 automatically scrammed due to a turbine trip. The turbine trip occurred during weekly turbine trip testing. Two safety relief valves actuated (and reseated) in the relief mode on the turbine trip. The reactor water cleanup system isolated during the transient (not being reported as there was no isolation in multiple systems). The plant is stable with reactor pressure control to the main condenser via the main steam isolation valves. The plant is planning to remain in hot shutdown pending (turbine) electro-hydraulic (EHC) system troubleshooting and repair. All control rods fully inserted during the scram. The site is aligning the ring bus for the normal shutdown electrical lineup. Reactor water level is being maintained using the main feedwater system and decay heat is being removed via the turbine bypass valves. The licensee notified the NRC Resident Inspector.
ENS 452455 August 2009 12:00:00ColumbiaAutomatic ScramNRC Region 4GE-5

At 0750 PDT the licensee experienced a turbine trip and reactor scram. At approximately the same time, a fire was detected in the non-safety related 6.9 kV feed bus to switchgear SH-5 and SH-6 in the turbine building. The fire and associated fault to the switchgear feed bus caused a loss of power to both reactor recirculation pumps and the automatic reactor scram. The fire produced smoke and potentially toxic gases. Due to the presence of potentially toxic gas in the power plant, an Unusual Event was declared at 0812 PDT based on EAL 9.3.U.3. At the present time, the fire is out and the smoke is being cleared from the plant. All rods fully inserted upon the reactor scram. Systems functioned as expected except for problems with the EHC system which resulted in the bypass valves remaining open which caused the reactor to depressurize to approximately 390 psi. MSIVs were manually shut to halt the reactor depressurization and cooldown. Decay heat is being removed via relief valves to the suppression pool with reactor pressure being maintained between 500 and 600 psi. Suppression pool cooling is via RHR. Makeup water to the reactor is via normal feed. Licensee is on natural circulation at the time of this report. Normal shutdown electrical alignment is established with the exception of Division II emergency switchgear which is aligned to the backup transformer. A request for assistance was made to the Hanford fire department, however, the fire was out prior to their arrival on site. The licensee has notified State, local agencies and the NRC Resident Inspector.

  • * * UPDATE FROM JOHN SLACK TO DONALD NORWOOD AT 1332 ON 08/05/09 * * *

The Unusual Event has been terminated as of 1006 PDT. The licensee is taking the unit to cold shutdown. The licensee will notify the NRC Resident Inspector. Notified NRR EO (Ross-Lee), R4DO (Walker), DHS (Enzer), and FEMA (Eaches).

  • * * UPDATE FROM NICK RULLMAN TO PETE SNYDER AT 1827 ON 08/05/09 * * *

Following the reactor scram, with the turbine bypass valves failed fully open, the inboard main steam isolation valves had to be manually closed to prevent excessive cool down. The outboard main steam isolation valves automatically closed from the inability to maintain condenser vacuum. The inability to maintain condenser vacuum was due to limited equipment access in the Turbine Building from heavy smoke. This is reportable under Part 50.72(b)(3)(iv)(A) as a valid actuation of one of the systems listed in Part 50.72(b)(3)(iv)(B)(2). The licensee notified the NRC Resident Inspector. Notified R4DO (Walker).

ENS 4516926 June 2009 23:45:00ColumbiaManual ScramNRC Region 4GE-5

At 1949 PDT, a small fire was observed between the #1 and #2 bearings on the main turbine involving some lube oil leakage and lagging. The fire brigade was dispatched and at 1953 PDT, the reactor was manually scrammed. At 2005 PDT, the licensee declared an Unusual Event (EAL 9.2.U.1) based on a fire lasting greater than 15 minutes. At 2006 PDT, the fire was reported out. The manual scram was uncomplicated and all systems functioned as required. The reactor is being cooled by normal feedwater and discharging decay heat to the condenser. The licensee is cooling down the reactor to Mode 4. Currently reactor pressure is 495 psi. The licensee has stationed a re-flash watch at the fire location and is assessing any damage that may have occurred. The only damage currently reported involves lagging at the fire location. The NRC Resident Inspector, State and local authorities have been notified.

  • * * UPDATE FROM BILL HART TO HOWIE CROUCH @ 0128 EDT ON 6/27/09 * * *

The licensee terminated the NOUE at 2159 PDT. The termination criteria was the fire is out, a re-flash watch stationed and the plant is stable and transitioning to Mode 4. The licensee has made State and local notifications and has notified the NRC Resident Inspector. Notified R4DO (Powers), IRD (Grant), NRR ET (Lubinski), FEMA (Casto) and DHS (Vestal).

ENS 450518 May 2009 17:41:00ColumbiaManual ScramNRC Region 4GE-5At 1045 hours, a manual scram was inserted due to a loss of main generator seal oil pressure and subsequent loss of hydrogen pressure in the Main Generator. Initial investigation revealed that a filter in the seal oil system became clogged during a system test. Even though the test was stopped and the system lineup restored, seal oil system pressure did not return to normal until the main turbine generator was secured. No indications of turbine or generator damage exist. All rods fully inserted, MSIVs remained open, no SRVs opened, and all other safety systems operated as designed. Reactor Water Level was restored and maintained with the Reactor Feedwater and Condensate systems during the post scram transient within normal operating bands. Reactor Pressure was controlled using the Main Turbine Bypass Valves in automatic control. Normal cool down to the Main Condenser is in progress. Offsite power is available. EDG-2 was inoperable but available due to surveillance testing, restoration is in progress. All other EDGs are operable and in standby status. This shutdown occurred 13 hours before a planned shutdown for the refueling outage, so the plant will not be restarted until after the outage. The licensee notified the NRC Resident Inspector.
ENS 448398 February 2009 18:08:00ColumbiaAutomatic ScramNRC Region 4GE-5Following a downpower to 75% for replacement of DEH-SV-TRIP/B (solenoid for quadvoter valve) a reactor SCRAM occurred during the performance of the DEH (Digital Electric Hydraulic) quadvoter valve testing. The cause of the reactor SCRAM was Governor Valve Fast Closure signal due to DEH trip header pressure fluctuation. The cause of the DEH trip header pressure fluctuation is unknown and being investigated. All rods fully inserted. MSIVs remained open. No SRVs opened. RPV level is being controlled in the normal band using the feedwater and condensate systems. RPV pressure is being controlled in the normal band using the Bypass valves and Main Steam Line drains. All other safety systems operated as designed. Off-site power is available. All three emergency diesel generators are operable and available. The licensee will be making a press release. The licensee notified the NRC Resident Inspector.
ENS 4443221 August 2008 22:30:00ColumbiaAutomatic ScramNRC Region 4GE-5Following a downpower to 65% for maintenance on one of the reactor feedwater turbines, a main turbine digital electro-hydraulic (DEH) quadvoter valve, that had failed a previous surveillance, was replaced. During the operability testing of the new DEH quadvoter valve, a leak developed. DEH reservoir level dropped 8 inches (approx. 52 gal) and tripped the main turbine on low DEH pressure. An automatic reactor trip occurred due the main turbine trip. All rods fully inserted. RPV pressure was controlled using the bypass valves and main steam line drains. No SRV's opened. RPV level was maintained using the feedwater and condensate system in the normal RPV level band. All other safety systems operated as designed. Off-site power is available. Three emergency diesel generators are operable and available. The licensee has notified the NRC Resident Inspector.
ENS 4345728 June 2007 21:53:00ColumbiaAutomatic ScramNRC Region 4GE-5Reactor trip at 1717 hrs PDT due to (condensate pump) COND-P-2B trip. Reactor power was at 70% with (condensate pump) COND-P-2A secured. Reactor vessel level reached -50 inches and was restored with High Pressure Core Spray and Reactor Core Isolation Cooling. Main Steam Isolation Valves closed as expected due to the reaching -50 inches. All systems operated as expected. Further investigation into COND-P-2B trip is underway. Plant is stable in mode three, heat removal is being maintained by RHR-P-2B and Safety Relief Valves. All rods fully inserted on the automatic reactor scram. All safety systems were available at the time of the trip. The trip was considered uncomplicated. The reactor pressure is currently being maintained between 500 to 600 psi and water level between 60 to 80 inches. The licensee was at 70% power at the time of the trip due to maintenance of condensate pump P-2A. The licensee will notify the NRC Resident Inspector.
ENS 4240310 March 2006 00:58:00Nine Mile PointAutomatic ScramNRC Region 1GE-5

This notification is being made in accordance with 10 CFR 50.72(b)(2)(iv)(B) RPS Actuation (scram) for Nine Mile Point Unit 2 which states 'Any event or condition that results in actuation of the reactor protection system (RPS) when the reactor is critical except when the actuation results from and is part of a pre-planned sequence during testing or reactor operation.' On 03/09/2006 at 2214 while operating at approximately 85 % reactor power (coast down to refueling) a condenser low vacuum condition resulted in a turbine trip and a subsequent reactor scram. A loss of sealing steam most probably caused the loss of condenser vacuum and an investigation is in progress. Special Operating procedure N2-SOP-101 C was entered. All control rods inserted (fully) as expected. Condenser vacuum has been stabilized and the main steam isolation valves are open. The plant is stable and recovery actions are in progress. Decay heat is being removed via the turbine bypass valves to the main condenser. The condensate and feedwater system is in operation maintaining reactor vessel level. The electric plant is in a normal shutdown lineup and there was no effect from this transient on Unit 1. The licensee notified the NRC Resident Inspector.

  • * * UPDATE AT 0035 EST ON 3/14/06 FROM P. WALSH TO W. GOTT * * *

This update is being made to provide additional information to EN# 42403 which was communicated via ENS on 3/10/06 at 0058 hours. During the scram that occurred at Nine Mile Point Unit 2 on 3/9/06 at 2214 hours, a primary containment isolation signal to RHR Shutdown Cooling, RHR Head Spray and RHR sample valves was received as designed. No components repositioned as the valves are normally closed during plant operations. The licensee will notify the NRC Resident Inspector. Notified R1DO (P. Krohn).

ENS 4234820 February 2006 02:14:00LaSalleAutomatic ScramNRC Region 3GE-5

While shutting down Unit 1 IAW LGP-2-1 with the main turbine off line the plant experienced a turbine control system (EHC) malfunction. This resulted in opening all main turbine bypass valves and subsequent reactor low pressure condition. The low pressure condition resulted in a closure of all main steam isolation valves (MSIV's) and automatic reactor scram. Three rods failed to indicate fully inserted on the scram. Plant emergency operating procedures were entered. All ECCS and plant systems operated as expected. All control rods are fully inserted and the ATWS emergency operating procedure has been exited. The main turbine had been taken off line prior to this event and shutdown was being conducted with heat removal on the bypass valves. Pressure control is currently by using the steam line drains with the Safety Relief Valves in manual. Level is being maintained using normal feedwater. The electrical grid is stable though the plant is not yet on backfeed. Diesel generators are operable. The licensee will notify the NRC Resident Inspector. The NRC entered Monitoring Mode at 0243. Notified R4DO (Graves), DHS (SWO), FEMA (J Kanupp), DOE (S. Morrone), EPA(NRC) (Nowak), USDA (Amanda), HHS (Kleiman).

  • * * UPDATE AT 0402 ON 2/20/2006 * * *

In addition to the initial notification, La Salle is reporting a group 1 isolation in accordance with 10CFR50.72(b)(3)(iv)(a).

  • * * UPDATE AT 0435 ON 2/20/2006 * * *

The site exited the Site Area Emergency and entered the recovery phase.

  • * * UPDATE AT 05:59 ON 2/20/2006 * * *

At the time of the scram @ 0023 hours rod 38-43 showed position 24 and rods 26-15 and 34-47 showed unknown. Based on more than one rod out condition, it is unanalyzed until shutdown margin can be verified.

  • * * UPDATE AT 0655 ON 2/20/2006 * * *

NRC exited Monitoring Mode. Notified IRD (Wilson), NRR EO (J. Lyons), R3DO (Lara), R4DO (Graves), NRR (Dyer), DHS (SWO), FEMA (Eerwin), DOE (Joe Stambaugh), NRC (does not take updates), USDA (Jim Brzostek), HHS (SOC) (Lt Hrynyshen).

  • * * UPDATE FROM DAN COVEYOU TO JOE O'HARA AT 0700 ON 02/22/06 * * *

Post trip evaluations have confirmed that all control rods were fully inserted within four minutes of the reactor scram. A review of the post-trip data suggests that there were only control rod indication problems on the three subject rods and all control rods were fully inserted immediately at the time of the reactor scram. Follow-up evaluations also demonstrated that even if the three subject control rods remained fully withdrawn in a cold shutdown condition, the reactor would have remained adequately shutdown. Additional confirmatory evaluations are continuing. The licensee issued a press release on this event. The licensee notified the NRC Resident Inspector. R3DO(Hills) has been notified.

ENS 4179023 June 2005 18:50:00ColumbiaAutomatic ScramNRC Region 4GE-5On June 23, 2005 at 1348 PDT Columbia Generating Station experienced a Reactor Protection System (RPS) actuation and closure of all Main Steam Isolation Valves (MSIV) while operating at approximately 25% power. Currently, Reactor Pressure Vessel (RPV) level is being controlled using the Reactor Core Isolation Cooling (RCIC) system and RPV pressure is stable at approximately 800 psi. There was no automatic ECCS system injection. At this time, the plant is stable and indications show that the RPS actuation and closure of MSIVs was initiated in response to a valid low RPV water level signals that occurred because of a loss of feedwater flow. Determination of the cause of the loss of feedwater flow is ongoing at this time. All control rods fully inserted. The licensee informed the NRC Resident Inspector.
ENS 4177915 June 2005 18:38:00ColumbiaAutomatic ScramNRC Region 4GE-5On June 15, 2005 at 1400 PDT Columbia Generating Station experienced a Reactor Protection System (RPS) actuation while operating at full power. Currently, reactor level is being controlled with the feedwater system and reactor pressure is being controlled via the turbine bypass valves to the condenser. All safety systems functioned as expected and there was no ECCS system injection. The initial attempt to trip the main turbine from the control room was unsuccessful and it was subsequently tripped locally. At this time the plant is stable and indications show that the RPS actuation originated from closure of turbine throttle valves. Determination of the cause of the RPS actuation is ongoing at this time. All rods fully inserted and no relief valves lifted. The NRC Resident Inspector was notified.
ENS 415604 April 2005 13:19:00LaSalleManual ScramNRC Region 3GE-5The following information was obtained from the licensee via facsimile (licensee text in quotes): This telephone notification is provided in accordance with 10 CFR 50.73(a)(1), to report an invalid actuation reportable under 10 CFR 50.73(a)(2)(iv)(A). On February 7, 2005, at 0756 (CST), with Unit 2 in Mode 3 'Hot Shutdown' in preparation for the 2005 refueling outage, the 2A Reactor Protection System (RPS) bus unexpectedly de-energized during performance of LOS-RP-W1, 'Manual Scram Instrumentation.' As a result, an RPS Bus A half scram and Division 1 Primary Containment Isolation System (PCIS) isolations were received, including the isolation of shutdown cooling. All affected containment isolation valves closed as designed. An inspection found that the 2A RPS MG set output breaker had opened. RPS Bus A was transferred to its alternate feed, and the associated containment isolations were reset. Shutdown cooling was restored at 0845 hours on February 7, 2005. Troubleshooting found that the 2A RPS MG set voltage regulator had failed. The voltage regulator was replaced and successfully tested, and the 2A RPS MG set was returned to service. Laboratory testing of the failed voltage regulator circuit board found that a solder joint had failed on load-dropping resistor R8, which caused the excitation output voltage to decrease sharply. This resulted in a trip of the 2A RPS MG set output breaker on low voltage. The apparent cause of the failed solder joint was a manufacturing defect. Corrective actions include visual inspections of RPS MG set voltage regulatory circuit boards in the field and in the storeroom, and the development of enhanced receipt inspection requirements. This event is reportable under 10 CFR 50.73(a)(2)(iv)(A) as an invalid actuation of containment isolation valves in more than one system. The licensee has notified the NRC Resident Inspector.
ENS 4096417 August 2004 11:46:00ColumbiaManual ScramNRC Region 4GE-5With a reactor startup in progress at 0528 PDT, operators at Columbia Generating Station inserted a manual reactor scram when the operating Reactor Feed Water (RFW) pump RFW-P-1A tripped. Reactor power was approximately 20% at the time of RFW pump trip. The cause of the RFW pump trip was due to low suction pressure; the cause of the low suction pressure is currently under investigation. The Reactor Core Isolation Cooling (RCIC) system (was manually started and) was used to maintain reactor vessel water level until reactor pressure was reduced to within the capacity of the condensate booster pumps (500 to 600 psi). The RCIC system has been returned to a standby lineup. The reactor is in Mode 3 (Hot Shutdown) with both reactor recirculation pumps running at minimum speed (15 Hertz). Decay heat is being rejected to the main condenser via auxiliary steam loads. All ECCS systems are operable. All emergency diesel generators are operable. No Safety Relief valves lifted during the scram. The NRC Resident Inspector was notified of this event by the licensee. See similar event number 40959 that occurred on 08/15/04.
ENS 4095915 August 2004 19:24:00ColumbiaManual ScramNRC Region 4GE-5With a reactor startup in progress at 1303 PDT, operators at Columbia Generating Station inserted a manual reactor scram when the running Reactor Feedwater (RFW-P-1A) pump tripped. Reactor power was approximately 18% at the time of RFW-P-1A trip. The cause of the RFW-P-1A trip was a high RFW Turbine Drain Tank (MD-TK-1) level; the cause of the MD-TK-1 high level is under investigation. The Reactor Core Isolation Cooling (RCIC) was used (manually started) to maintain reactor vessel water level until reactor pressure was reduced to within the capacity of the condensate booster pumps; the RCIC system has been returned to a standby lineup. The reactor is in mode 3 with both reactor recirculation pumps running at minimum speed (15 Hertz). Decay heat is being rejected to the main condenser via auxiliary steam loads. One control rod that indicated full-in immediately after the scram lost full-in indication eleven seconds after the scram. This control rod indicated full-in again 84 seconds after the scram. This ENS notification is made pursuant to 10 CFR 50.72(b)(2)(iv)(B). The licensee has notified the NRC Resident Inspector.
ENS 4035727 November 2003 03:24:00LaSalleManual ScramNRC Region 3GE-5A manual reactor scram was initiated due to a decreasing reactor vessel water level. The decreasing water level occurred during a feedwater transient while performing a power reduction in preparation for taking the main generator off line for maintenance. The licensee is investigating the cause of the feedwater transient, but it occurred while one turbine driven reactor feed pump was being taken off line. All rods fully inserted following the scram and no ECCS or safety relief valves actuated. Residual heat is being rejected to the condenser. The licensee notified NRC Resident Inspector.